Among image forming apparatuses such as laser beam printers, there are those in which a developing unit provided with a memory can be attached to and detached from the image forming apparatus unit. In such image forming apparatuses, information is written into and read from an element provided on the developing unit.
There are also image forming apparatuses that have AC voltage supply sections. In such image forming apparatuses, an AC voltage is supplied from the AC voltage supply section to, for example, the developing device or the charging device, and this AC voltage is used for developing latent images or charging the photoconductor.
However, it is necessary that information is accurately written into and read from the memory. For example, when writing information about the remaining amount of toner into the memory provided on the developing unit, if incorrect information is written, then the amount of toner remaining in the developing unit cannot be managed properly.
The present invention has been made in view of the foregoing problem, and it is an object thereof to achieve image forming apparatuses and computer systems with which information can be accurately written into developing units having elements, for example.
It is a further object of the present invention to achieve developing units, image forming apparatuses, and computer systems with which communication with an element can be carried out accurately.